The invention relates to a multiplexer including an arrangement for combining at least two source signals to a multiplex signal, in which the source signals from independently operating source modules are transmitted to a multiplex module in which they are combined to the multiplex signal in a predetermined manner. Such a multiplexer is known from EP 460835.
When a plurality of source signals is combined to a multiplex signal, the source signals should be synchronized in the phase position, converted to the target frequency and combined in a predetermined sequence. This problem occurs, for example in the Synchronous Digital Hierarchy. This object is sometimes even more difficult to realise in that the source modules supplying the source signals operate independently of each other and their output signals have to be combined to a multiplex signal in another module. In accordance with the prior art this object is generally solved by means of a method referred to as master-slave method in which one of the modules, generally the multiplex module, becomes the master of and controls the other modules.